Floating solar farms can help protect lakes and reservoirs from harmful effects of climate changes.
Scientists from the Universities of Lancaster and Stirling have completed the first detailed modelling of the impact of floating solar installations on an aquatic environment. Floating solar farms could help protect lakes and reservoirs from some of the dangers of climate change, according to a new study. However, given the complexity of water bodies and the different designs of solar technology, the deployment of floating solar arrays could also have adverse impacts on the ecosystem. Traditional solar farms are controversial because of the amount of land they take up. This has led to a growing interest in floating solar farms.
So far, there are three commercial-scale floating solar arrays in the UK and hundreds more around the world. The number of installations is likely to increase significantly in the coming decades as more countries commit to net zero carbon targets and the demands for renewable energy rise. However, until now, little people know about the positive and negative effects of these floating solar farms on lakes and reservoirs.
Scientists from the Universities of Lancaster and University of Stirling University have completed the first detailed modelling of the impact of floating solar installations of
floating solar systems on an aquatic environment.
"As the demand for land increases, water bodies are increasingly targeted for renewable energy.” Deploying solar energy on water increases the amount of electricity generated, but it is crucial to know whether there will be any positive or negative environmental consequences," said Dr Researcher and lead author Mr Giles Exley, from Lancaster University. Given the relative immaturity of floating solar farms, it is important to demonstrate their impact further scientifically. "Our results provide an initial insight into key impacts, which will help inform decision-making by water managers and policymakers."
The team built a computer model using the MyLake simulation program and data collected by the UK Centre for Ecology and Hydrology from Windermere, England's largest lake. While researchers believe it is unlikely that a floating solar farm could be deployed on Lake Windermere, it provides a rich data set because it is one of the most thoroughly studied lakes in the world.
Their results show that floating solar arrays can cool water temperatures by blocking out the sun. On a scale, this could help mitigate the harmful effects of global warming, such as blooms of toxic blue-green algae, and increased the evaporation of water, which could threaten water supplies in some areas.
Scientists have found that floating solar devices also reduce the duration of "layering" - the heating of water by the sun, which creates layers of water at different temperatures. This tends to occur more often during warm summer months and can lead to deoxygenation of the bottom layer of water, which in turn worsens water quality. It is an obvious problem for drinking water supplies. However, the situation is complex under some conditions. The adverse effects of man made changes in stratification problems on water quality which may increase if floating solar farms increase. As the effect of floating solar energy on water temperature and stratification is a major driver of biological and chemical processes, the effect could be on a scale comparable to that of climate change in lakes. Floating solar energy could help mitigate the negative effects that global warming will have on these bodies of water. However, there is also a real risk of adverse effects. We need more research to understand the possibility of positive and negative effects.
The larger the solar installation, the greater the impact on water temperature. Small arrays less than 10 percent of the lake generally have the least impact. However, a single lake is currently focused on this model, and further research is needed to determine the optimal array size and design, as well as their impact on individual lakes and reservoirs. All of them have unique characteristics. Different designs of solar installations also provide different shades from the sun and wind.
The study found that an array covering more than 90 percent of the lake could increase the chance of freezing in the winter - though these effects also vary by water body and installation design and need to be studied further.
Based on these initial findings, the field studies and further modeling work are ongoing.